changed batteries... now truck has gremlins UPDATE

[camiswelding]

After I put optimas in my truck it was hard to start... like the choke wasnt working...(fuel pumps and filters are recent) I noticed my fast idle also isnt there now... truck runs perfect otherwise.. has 40k on it
Manual says that if the computer loses power it may take up to 40 miles for it to reprogram itself (I havent driven 40 miles with it)
Anyone ever experience anything like this... its got me stumped... my SB v3500 never exibited anything like this when the batteries were disconnected...
OBD reader shows no fault codes
thnaks
cam

 

[1-ton]

Re: changed batteries... now truck has gremlins 89 tbi bb v3500 cc 3+3

It sounds like bit of a stumper. Since your fast idle for engine warm up is not working, it does sound computer related. You could try clearing the computer by either removing both battery cables and touching them together; or the GM factory way mechanics in a shop clear it by taking the computer interface connector, under the dashboard close to the steering column, and jump two of the pins (it has been so long since I have done it, I cannot remember which pins, but your manual might have that info) with a paper clip and then turn the key to the "accessory" position.

The reason shop mechanics do it the factory way is to keep the radio presets where they are, so the customer does not get mad. Also, vehicles with air bags could possibly deploy their air bags if you use the battery cable method.

I have a V/3500 3+3 Crew-Cab 4X4 P/U myself.

 

[75-K5]

Re: changed batteries... now truck has gremlins 89 tbi bb v3500 cc 3+3

I think it is the two top-right pins. /forums/images/graemlins/thinking.gif At least I think those are the pins to check the codes. I ran some codes once and couldn't remember exactly which pins to cross, so I just used trial and error.

 

[camiswelding]

Re: changed batteries... now truck has gremlins 89 tbi bb v3500 cc 3+3

ok.. Ill look at that... thanks for the tip
cam

 

[camiswelding]

Re: changed batteries... now truck has gremlins 89 tbi bb v3500 cc 3+3

ok well I disconnected the power to the system.... took the battery cables off (again) nd let it sit the requsite 10 seconds plus to clear the codes...
didnt help..
I did notice my check engine light does not come on upon startup.... its does function while running if I plug the reader into it...
any ideas?